Hello and welcome to HCM
You have mentioned that your 13 year old child is having high grade fever along with pain in the legs.
Thiese symptoms point towards a viral cause.
Viral infections are associated with high grade fever and
body ache.
Viral fevers has a self limiting course.
They affect an individual for around 7-10 days irrespective of the type or duration of medication taken.
Thereafter, the infection is resolved on its own.
You need to give symptomatic relief.
Advil (
Ibuprofen) is an anti-iflammatory and
analgesic (pain killer). It will relieve the pain in the legs.
Icing can be continued as it will reduce the temperature.
A nasal decongestant like one containing
oxymetazoline. For cough, saline gargles and a
mild cough syrup like Honitus can be used.
Take rest and don't worry.
Thanks and take care
Dr Shailja P Wahal